Hi all,
When looking at the following explanation: https://docs.nvidia.com/jetson/archives/l4t-archived/l4t-3271/index.html#page/Tegra%20Linux%20Driver%20Package%20Development%20Guide/adaptation_and_bringup_xavier_nx.html#wwpID0E0NL0HA
To calculate the pin number (“Hence, the GPIO number of GPIO3_PZ.07 is 320+(8*25)+7 = 527”)
However this does not match the pin numbers I am seeing on my Jetson?
When I check with cat /sys/kernel/debug/gpio
I see gpio-499 (PZ.07)
Where does this difference come from?
hello r.vries,
please check release tag for your current release version, i.e. $ cat /etc/nv_tegra_release
assume you’re using JP-5.1.x release, it’s due to GPIO calculation range has changed.
Where can I find the updated GPIO calculation range? I am indeed on JP-5.1.x
Has the calculation actually changed or is there a bug?
hello Yolomei,
I meant there’s BUG for following that calculation formula to check GPIO numbers.
please read GPIO numbers through sysfs.
hello r.vries,
you may looking kernel init messages for allocation ranges.
for example, $ sudo dmesg | grep "registered GPIOs"
$ sudo dmesg | grep "registered GPIOs"
[ 3.054090] gpiochip0: registered GPIOs 504 to 511 on max77620-gpio
[ 7.286094] gpiochip1: registered GPIOs 335 to 503 on tegra194-gpio
[ 7.287796] gpiochip2: registered GPIOs 305 to 334 on tegra194-gpio-aon
system
Closed
April 26, 2023, 7:04am
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